Method and apparatus for launching and recovering a remote inspection device

ABSTRACT

The present disclosure relates to methods and apparatus for launch and recovery of a remote inspection device within a liquid storage tank. In one embodiment, the tank is accessed by opening an entrance hatch and then injecting a vapor suppression foam across a surface of a stored liquid mass to form a foam layer. A launching system having a remote inspection device is attached to the entrance hatch to define a launch and recovery space sealed from an external environment and isolated from the stored liquid mass in the tank via a valve and the foam layer. The launch and recovery space is purged of hazardous vapors by injection of an inert gas prior to launch and recovery of the remote inspection device. Prior to removal of the launching system, the surface of the stored liquid mass is re-coated with vapor suppression foam.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.16/539,697 filed Aug. 13, 2019, which claims priority from U.S.Provisional Application Ser. No. 62/718,145, filed Aug. 13, 2018, eachof which is hereby incorporated by reference in its entirety.

BACKGROUND Field

Embodiments of the present disclosure generally relate to methods andapparatus for inspection of liquid storage vessels, and moreparticularly, inspection of hydrocarbon storage tanks.

Description of the Related Art

Hydrocarbon-based fluids, such as crude oil and gasoline, are oftenstored in large hydrocarbon storage tanks built above ground. Thesestorage tanks are typically cylindrical in shape and formed of steel. Asa preventive measure against corrosion and the escape of stored productinto the surrounding environment, the storage tanks are coated andconnected to a sacrificial metal structure for cathodic protection.Despite these preventative measures, the storage tanks still remainvulnerable to the salts, acids, and other corrosive materials found inthe crude oil and refined hydrocarbon-based products they are meant tohold. Thus, routine and periodic inspections of the interiors of thestorage tanks are necessary to determine the integrity of suchstructures.

Though necessary, inspections of the storage tanks require a significantamount of time and effort in order to perform the inspections safely andthoroughly. Conventional inspections typically require taking thestorage tank out of service, draining all the stored hydrocarbonproducts from the tank, and deploying a human inspector into the tank toconduct the inspection while additional support personnel and equipmentare stationed nearby. Efforts have recently been made to utilize remoteinspection devices to allow inspection of the storage tanks withoutdraining the stored hydrocarbon products and deploying personneltherein. However, deployment of remote inspection devices remainsproblematic due to a lack of containment of hazardous vapors that arecontinuously volatilized from the stored hydrocarbon products. Currentremote inspection systems either do not provide proper containment ofthe hazardous vapors during inspection, or utilize a tethering systemfor the remote inspection devices that causes sealing issues andpotential contamination of the manway and its surroundings.

Accordingly, what is needed in the art are improved methods andapparatus for inspection of liquid storage vessels.

SUMMARY

The present disclosure generally relates to methods and apparatus forinspection of liquid storage vessels. In one embodiment, an apparatusfor inspection of a liquid storage vessel is provided. The apparatusincludes a chamber body having an internal volume partially defined byone or more sidewalls and a lid and a closure coupled to the chamberbody opposite of the lid and further defining the internal volume. Theapparatus further includes a gas injection port is disposed through thechamber body for delivering an inert gas into the internal volume and alifting system within the internal volume for transporting an inspectiondevice through the closure.

In one embodiment, a method for deploying an inspection device into ahazardous environment containing a mass of vaporizable liquid isprovided. The method includes providing a launching system having aclosed vessel with an inspection device disposed therein, forming avapor suppression layer on the liquid mass at an access passage of astorage tank, and attaching the closed vessel of the launching system tothe access passage. The method further includes inerting an internalvolume of the closed vessel of the launching system, opening the closedvessel to the access passage, and passing the inspection device from thelaunching system into the liquid mass.

In one embodiment, a method inspecting a storage vessel is provided. Themethod includes injecting a vapor suppression foam into an opening ofthe storage vessel to form a vapor suppression layer over a liquid masstherein and coupling a launching system having an inspection device tothe opening. A volume between the launching system and the vaporsuppression layer is inerted by injecting one or more inert gases intothe volume. A closure of the launching system is opened, and a cableremovably coupled to the inspection device is unwound to lower theinspection device into the liquid mass. When the inspection device is inthe storage vessel, the inspection device is uncoupled from the cable.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofits scope, and may admit to other equally effective embodiments.

FIG. 1 is a cross-sectional view of a launching system for a remoteinspection device according to an embodiment described herein.

FIG. 2 is a cross-sectional view of a launching system for a remoteinspection device according to an embodiment described herein.

FIG. 3 is a flow diagram of a process of launching a remote inspectiondevice with the launching system of FIG. 1 .

FIGS. 4A-4H are schematic cross-sectional views of the launching systemat different stages of a remote inspection device launching processaccording to an embodiment described herein.

FIG. 5 is a flow diagram of a process of recovering a remote inspectiondevice with the launching system of FIG. 1 .

FIGS. 6A-6H are schematic cross-sectional views of the launching systemat different stages of a remote inspection device recovery processaccording to an embodiment described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

The present disclosure relates to methods and apparatus for launch andrecovery of a remote inspection device within a liquid storage tank. Inone embodiment, the tank is accessed by opening an entrance hatch andthen injecting a vapor suppression foam across a surface of a storedliquid mass to form a foam layer. A launching system having a remoteinspection device is attached to the entrance hatch to define a launchand recovery space sealed from an external environment and isolated fromthe stored liquid mass in the tank via a valve and the foam layer. Thelaunch and recovery space is purged of hazardous vapors by injection ofan inert gas prior to launch and recovery of the remote inspectiondevice. Prior to removal of the launching system, the surface of thestored liquid mass is re-coated with vapor suppression foam.

FIG. 1 is a cross-sectional view of a launching system 100 for a remoteinspection device 150 according to one embodiment. The launching system100 includes a chamber body 102 having one or more sidewalls 104 and alid 106 at least partially defining a launch and recovery volume 110. Inone embodiment, the lid 106 is integrally coupled to the sidewalls 104.In one embodiment, the lid 106 is removably coupled to the sidewalls104. The chamber body 102 may have any suitable morphology anddimensions. In one embodiment, the chamber body 102 has a substantiallycylindrical shape. In another embodiment, the chamber body 102 has apolygonal shape, such as a rectangular shape or the like. In someembodiments, the chamber body 102 is shaped to correspond with amorphology of an opening or manway in a liquid storage tank. The chamberbody 102 is fabricated from a material suitable for maintaining a lowpressure and inerted environment therein, such as metallic materials,for example aluminum and titanium. In another aspect, the chamber body102 is fabricated from a metal alloy, for example stainless steel,carbon steel, hastelloy, and nickel alloy. Furthermore, the chamber body102 and any equipment or components coupled thereto are electricallybonded to match the electric potentials thereof. For example, thechamber body 102 and the equipment or components coupled thereto may beelectrically bonded via one or more bonding straps, bus bars, jumperwires, shunts, rods, adhesives, and other suitable electricalconnectors.

The chamber body 102 further contains a winch 140, a cable 142, and aremote inspection device 150 therein. The winch 140 may be coupled tothe chamber body 102 at any suitable location, such as for example, tothe lid 106 or a distal end of the sidewalls 104 as depicted in FIG. 1A.In one embodiment, the winch 140 is a manual hand winch having a handle144 disposed external to the launch and recovery volume 110 for manualhand crank operation. In another embodiment, the winch 140 is apneumatic winch to which compressed air may be fed in a locationexternal to the launch and recovery volume 110. In yet anotherembodiment, the winch 140 is a hydraulic winch. Rotation of the winch140 enables winding and unwinding of the cable 142, to which the remoteinspection device 150 is removably coupled at a distal end thereof.Thus, the remote inspection device 150 may be raised and lowered throughthe chamber body 102 by rotation of the winch 140 when the launchingsystem is in an upright position. In one embodiment, the cable 142 isfabricated from a material suitable to withstand a high tensiongenerated by the weight of the remote inspection device 150 when coupledthereto, such as a load capacity between about 200 pounds and about 500pounds. For example, the cable 142 is fabricated from a metallicmaterial such as aluminum, titanium, or a metal alloy. In some examples,the cable 142 is fabricated from the same metallic material as thechamber body 102.

The remote inspection device 150 includes any suitable submersibleapparatus for inspection of liquid-containing vessels. For example, theremote inspection device 150 is a submersible vehicle configured toperform tethered or tetherless inspection of liquid-containing vessels.In one embodiment, the remote inspection device 150 is controlled by auser at a remote location. Additionally or alternatively, the remoteinspection device 150 may have autonomous functionality. Generally, theremote inspection device 150 includes a chassis, a locomotion orpropulsion system, a power source, and one or more sensors forperforming inspection of liquid-containing vessels. Examples of sensorsthat may be integrated with the remote inspection device 150 to aid ininspection include an optical sensor, a magnetic field sensor, aphased-array ultrasonic testing system, a gyrocompass, an inertialnavigation system, a speed sensor, an acoustic ranging system, and anacoustic or Doppler sensor. In one embodiment, the remote inspectiondevice 150 includes a nose cone (not shown) having a substantiallyconical shape for centering the remote inspection device 150 upon entryinto the launching system 100 during recovery thereof. For example, thenose cone may be utilized to guide and stabilize the remote inspectiondevice 150 while the remote inspection device 150 is raised through alower opening of the launching system 100.

In one embodiment, one or more sets of device guides 152 are optionallydisposed within the launch and recovery volume 110 upon which the remoteinspection device 150 may be raised and lowered. In combination with thenose cone, the one or more sets of device guides 152 are utilized toposition and usher the remote inspection device 150 during launch andrecovery and prevent swinging thereof. For example, the one or more setsof device guides 152 may prevent collision of the remote inspectiondevice 150 with the sidewall 104 while the remote inspection device 150is being raised, lowered, or stored within the chamber body 102. In oneembodiment, the one or more sets of device guides 152 are rails, tracks,or slots disposed through the launch and recovery volume 110.

A pressure relief port 122, a test port 124, an inert gas injection port126, and an optional wash port 128 are disposed through the one or moresidewalls 104 and/or the lid 106. For example, the pressure relief port122, the test port 124, the inert gas injection port 126, and the washport 128 may be disposed at a distal end of the sidewalls 104. In oneembodiment, the pressure relief port 122 includes a y-type valve, ak-type valve, a spring-loaded valve, or any other suitable type ofautomatic control valve. The pressure relief port 122 functions as afail-safe to automatically release gases from the launch and recoveryvolume 110 when an internal pressure exceeds a desired or preset limit.The test port 124 provides a coupling for diagnostic equipment (notshown) to monitor one or more conditions of the launch and recoveryvolume 110. In one embodiment, the test port 124 may serve as an adaptorfor a pressure gauge, a temperature gauge, or the like. The gasinjection port 126 facilitates the delivery of one or more gases intothe launch and recovery volume 110, for example, during the launch andrecovery of the remote inspection device 150. In one embodiment, theinert gas injection port 126 is coupled to a gas supply (not shown)configured to supply one or more inert gases into the launch andrecovery volume 110, such as nitrogen, argon, and the like. Altogether,the pressure relief port 122, the test port 124, and the gas injectionport 126 are utilized to inert the launch and recovery volume 110 andmaintain a slight overpressure of inert gas above ambient atmosphericpressure therein during launch and recovery of the remote inspectiondevice 150. In one embodiment, the pressure relief port 122, the testport 124, and the gas injection port 126 are disposed in close proximityto one another for easier accessibility to a user.

In some embodiments, the launching system 100 may include the optionalwash port 128. The wash port 128 facilitates the delivery of one or morecleaning fluids into the launch and recovery volume 110. For example,the wash port 128 may be coupled to a cleaning fluid supply (not shown)configured to supply one or more cleaning fluids to the launch andrecovery volume 110 to clean the remote inspection device 150, cable142, and interior walls of the chamber body 102. Suitable cleaningfluids for use with the launching system 100 include non-corrosive orbiodegradable agents. In one embodiment, the wash port 128 is furthercoupled to an annular spray device 129, such as a showerhead, disposedbetween the winch 140 and the remote inspection device 150 and aroundthe cable 142. For example, the spray device 129 may be coupled to thechamber sidewalls 104 or the lid 106. The spray device 129 is utilizedto direct and distribute the cleaning fluids within the interior of thechamber body 102, such as against the cable 142, the remote inspectiondevice 150, and the interior walls of the chamber body 102.

One or more lifting lugs 127 are coupled to an exterior surface of thechamber body 102, such as the sidewalls 104 or the lid 106. Two liftinglugs 127 are shown coupled to the lid 106 in FIG. 1A. The lifting lugs127 provide anchor points for one or more cables of a lifting device(not shown) to attach thereto and hoist the launching system 100 onto oroff of the liquid storage tank. For example, the launching system 100may be lifted onto a roof of the storage tank via a crane or othersuitable device having a hoisting cable attached to the lifting lugs127. In one embodiment, the lifting lugs 127 are formed of a materialsimilar to that of the chamber body 102, such as aluminum, titanium, ora metal alloy.

A closure 108 is coupled to the chamber body 102 at a flange 105 andfurther defines the launch and recovery volume 110. The closure 108enables opening and closing of the launch and recovery volume 110 to anexternal environment, such as the interior of the liquid storage tank.In some embodiments, the closure 108 is a ball valve, a plug valve, orthe like. Similar to the chamber body 102, the closure 108 is fabricatedfrom a material suitable for maintaining a low pressure environmentwithin the launch and recovery volume 110, such as metallic materialslike aluminum, titanium, stainless steel, and other metal alloys.

In one embodiment, the closure 108 is a knife gate valve or a slide gatevalve having a frame 107 and a gate blade 118. The frame 107 and thegate blade 118 are shaped to correspond with the shape of the chamberbody 102. For example, if the chamber body 102 is cylindrical, the frame107 may be annular and the gate blade 118 substantially circular. Inanother example, if the chamber body 102 is rectangular, the frame 107and the gate blade 118 may be substantially quadrate. In one embodiment,the frame 108 has one or more gate seats 109 through which the gateblade 118 is actuated. When in a closed position 112, the gate blade 118is configured to seal the launch and recovery volume 110 from anexternal environment, for example the interior of the liquid storagetank. In one embodiment, the closure 108 includes a gate blade actuator(not shown), such as an external hand-wheel threaded onto a screwattached to the gate blade 118. When the hand-wheel is rotated, thescrew is axially moved by the wheel, causing the gate blade 118 to bemoved in a first or second direction.

The closure 108 is coupled to a tank adapter 114 on a side thereofopposite the chamber body 102. The tank adapter 114 facilitates couplingof the launching system 100 to an opening of the liquid storage tank,such as a manway or hatchway of the liquid storage tank. The tankadapter 114 is fabricated from a material suitable for maintaining a lowpressure environment therein, such as metallic materials like aluminum,titanium, stainless steel, and other metal alloys. In one embodiment,the tank adapter 114 adapts the dimensions of the chamber body 102and/or closure 108 to dimensions and morphologies of the liquid storagetank opening. For example, the tank adapter 114 adapts the diameter ofthe chamber body 102 adjacent the closure 108 to a diameter of theliquid storage tank opening. In one embodiment, the tank adapter 114 hasan inner diameter lesser than an inner diameter of the chamber body 102and/or an inner diameter of the closure 108 to account for manways orhatchways having smaller dimensions. Furthermore, the tank adapter 114may have a lower annular surface 115 wide enough to adapt the launchingsystem 100 to liquid storage tank openings having both narrower andwider diameters or widths, such as openings ranging in diameter/widthbetween about 18 inches and about 36 inches, such as between about 24inches and about 30 inches.

In one embodiment, the tank adapter 114 has a bolt pattern that matchesa bolt pattern of the liquid storage tank opening, enabling directbolting of the launching system 100 to the liquid storage tank. Inanother embodiment, the tank adapter 114 is clamped to the opening ofthe liquid storage tank by an external clamping system or device, suchas a quick-latch system (not shown). For example, the tank adapter 114is clamped to the opening of the liquid storage tank by a pull-actionlatch or toggle clamp, such as a U-hook type clamp, a J-hook type clamp,or the like. The utilization of a quick-latch system enables quick andefficient coupling of the launching system 100 to the liquid storagetank opening. The lower annular surface 115 of the tank adapter 114 mayfurther include one or more grooves 117 for placement of one or moreseals therein (not shown), thus enabling the creation of a hermetic sealbetween the launching system 100 and the storage tank during coupling.For example, the lower annular surface 115 of the tank adapter 114 mayinclude one or more annular grooves 117 therein configured to supportone or more o-rings (not shown). The one or more seals may be formed anysuitable sealing materials, including but not limited to FFKM, PTFE,PEEK. Additionally or alternatively to the grooves 117, the tank adapter114 may be configured to be coupled to a gasket disposed between thetank adapter 114 and an opening of the liquid storage tank duringoperation of the launching system 100.

The tank adapter 114 includes one or more release ports 132 and one ormore injection ports 134. The release ports 132 may include a vent port,a test port, a pressure relief port, and/or the like. In one embodiment,one or more gauges, such as a temperature gauge and a pressure gauge,may be coupled to the release ports 132. In one embodiment, the one ormore release ports 132 include a pressure relief port substantiallysimilar to the pressure relief port 122 described above. The injectionports 134 may include a foam injection port, an inert gas injectionport, and/or the like. In one embodiment, the one or more injectionports 134 include an inert gas injection port substantially similar tothe inert gas injection port 126. Altogether, the release ports 132 andthe injection ports 134 may be utilized to assess, monitor, and controlthe conditions of a storage tank vapor gap (e.g. intermediate volume 478in FIG. 4D) prior to opening of the closure 108 and launch or recoveryof the remote inspection device 150.

FIG. 2 is a cross-sectional view of a launching system 200 configured tolaunch and recover the remote inspection device 150 according to oneembodiment. The launching system 200 is substantially similar to thelaunching system 100 and includes all the features described withreference to FIG. 1 , but further includes a transport system 260coupled thereto. Accordingly, only the transport system 260 will bedescribed with reference to FIG. 2 .

The transport system 260 is configured to facilitate both vertical andhorizontal transport of the launching system 200 along a roof of theliquid storage tank, thus enabling quick and efficient coupling of thelaunching system 200 to the opening of the liquid storage tank forengagement therewith. In one embodiment, the transport system 260 isremovably (or fixedly) coupled to the chamber body 102 of the launchingsystem 200 at an end thereof adjacent to the closure 108 and tankadapter 114. The transport system 260 may include three or more wheelassemblies 262 and wheel mounts 264 to facilitate horizontal movementthereof. In such examples, the wheel mounts 264 may be directly orindirectly coupled to the chamber body 102. In one embodiment, thetransport system 260 includes a transport frame 266 for coupling thewheel mounts 264 to the chamber body 102. For example, the transportframe 266 may include an annular frame coupled to and substantiallysurrounding a circumference of the chamber body 102. In one embodiment,the wheel mounts 264 are attached to the transport frame 266 usingpivoting arms and ball joints (not shown), thereby providing morefreedom for placement of the wheel assemblies 262 relative to thetransport frame 266 in case of obstructions around the opening of theliquid storage tank, such as rolling ladders.

The wheel assemblies 262 may generally include a wheel, a wheel frame,and a brake. For example, in one embodiment, the wheel assemblies 262include a caster, such as a swivel caster or a ball caster. In suchembodiments, the wheel assemblies 262 facilitate 360° directionalhorizontal movement of the launching system 200. The wheel assemblies262, the wheel mounts 264, and the transport frame 266 are fabricatedfrom any suitable materials capable of withstanding a load capacity ofthe launching system 200 and the remote inspection device 150. Forexample, the wheel mounts 264 and the transport frame 266 are fabricatedfrom metallic materials such as aluminum, titanium, stainless steel, andother metallic alloys. In one embodiment, the wheels are pneumatic orfoam-filled wheels configured to withstand the load capacities describedabove, in addition to shock loads from impacts caused by uneven surfacesof the liquid storage tank. Accordingly, the wheels may absorb theimpact shock and cushion the launching system 200 during transportthereof.

The transport system 260 further includes a vertical actuator tofacilitate vertical movement of the launching system 200, thus enablinglowering and/or raising of the launching system 200 to/from the openingof the liquid storage tank. In one embodiment, the vertical actuator isa mechanical actuator, a hydraulic actuator, a pneumatic actuator, orthe like. For example, the vertical actuator may be a mechanicalactuator configured to convert rotary motion of a hand-wheel or handleinto linear vertical displacement of the launching system 200, such as ajack screw, a house jack, or the like.

FIG. 3 illustrates a flow diagram of a representative method 300 oflaunching a remote inspection device, such as the remote inspectiondevice 150, with the launching systems 100, 200 of FIG. 1 and FIG. 2 .FIGS. 4A-4H illustrate schematic, cross-sectional views of the launchingsystem 100 at different stages of the method 300. Thus, reference toFIGS. 4A-4H will be included in the discussion of FIG. 3 and the method300 where warranted. Although FIGS. 4A-4H depict the launching system100, it should be understood that the method 300 may be performedutilizing the launching system 200 as well.

The method 300 for launching the remote inspection device 150 hasmultiple operations. The operations can be carried out in any suitableorder or simultaneously (except where the context excludes thepossibility), and the method can include one or more other operationswhich are carried out before any of the defined operations, between twoof the defined operations, or after all of the defined operations(except where the context excludes the possibility). Not all embodimentsinclude all the operations described.

In general, the method 300 includes controlling the volatilization of astored liquid mass in a liquid storage tank by injecting a layer ofvapor suppressing foam thereon at operation 310. At operation 320, aninerted launching system, such as the launching system 100, is coupledto and sealed against an opening of the liquid storage tank. An inertgas is then supplied to a space above the liquid mass in the liquidstorage tank at operation 330. At operation 340, a valve integrated withthe launching system, such as the closure 108, is opened, thus exposingan internal volume of the launching system to the vapor space. Atoperation 350, a remote inspection device disposed within the launchingsystem, such as the remote inspection device 150, is transferred intothe liquid storage tank via a winch and cable. Upon reaching a bottomsurface of the liquid storage tank, the remote inspection devicedetaches itself from the cable at operation 360. At operation 370, thecable is rewound into the launching system and the closure is closed.

In one embodiment, the method 300 begins with operation 310,corresponding to FIGS. 4A and 4B. At operation 310, a cover plate 462 isremoved from an opening 464 of a liquid storage tank 400 containing aliquid mass 466. The liquid storage tank 400 may be any suitable type ofstorage tank for the storage of liquids, including but not limited tofixed roof tanks, external floating roof tanks, internal floating rooftanks, spherical tanks, bullet tanks, and the like. Examples of liquids466 stored in the liquid storage tank 400 may include crude oil,gasoline, naphtha, diesel, kerosene, fuel oil, other petroleumcombustibles and distillates, and the like. The opening 464 may be anysuitable opening in the liquid storage tank 400, such as a manway,manhole, or other type of opening.

After removal of the cover plate 462, vapors accumulated in a vaporspace 468 of the liquid storage tank 400 are released into an externalenvironment 482. Thus, a vapor suppression foam 470 may be immediatelyinjected through the opening 464 to form a layer of the vaporsuppression foam 470 atop the liquid mass 466. By completely coveringthe liquid mass 466 with the layer of vapor suppression foam 470, anyfurther volatilization and release of vapors from the liquid mass 466into the external environment is suppressed or prevented.

In one embodiment, the vapor suppression foam 470 is a firefightingfoam, such as a class B foam designed to contain explosive vaporsproduced by flammable liquids. In one example, the vapor suppressionfoam 470 is a synthetic foam, such as an aqueous film forming foam(AFFF) or an alcohol-resistant aqueous film-forming foam (AR-AFFF). Inanother example, the vapor suppression foam 470 is a protein based foam,such as a regular protein foam (P), a fluoroprotein foam (FP), afilm-forming fluoroprotein foam (FFFP), an alcohol-resistantfluoroprotein foam (AR-FP), or an alcohol-resistant film-formingfluoroprotein foam (AR-FFFP). The vapor suppression foam 470 is injectedinto the vapor space 468 via a foam delivery system 472. In oneembodiment, the foam delivery system 472 is a handheld compressed airfoam system.

At operation 320, the launching system 100 is coupled to the liquidstorage tank 400, depicted in FIGS. 4C and 4D. The coupling of thelaunching system 100 and the opening 464 forms an intermediate volume478 between the layer of vapor suppression foam 470 or liquid mass 466and the closure 108. In one embodiment, the launching system 100 islowered onto the opening 464 by a crane or other suitable lifting device(not shown) attached to one or more lifting lugs coupled to the chamberbody 102. In an alternative embodiment, the launching system 100 islowered onto the opening 464 by adjusting the vertical actuator of thetransport system 260 to a desired height after the launching system 100has already been hoisted unto a roof of the liquid storage tank 400 andtransported thereacross to the opening 464.

Once the launching system 100 is aligned with the opening 464, the tankadapter 114 is bolted or clamped to a flange 465 of the opening 464using a latching mechanism 469. In one embodiment, a gasket 467 isinstalled on the flange 465 prior to coupling with the tank adapter 114,thus enabling a hermetic seal between the opening 464 and the launchingsystem 100. The gasket 467 may be formed of any suitable sealingmaterials, including but not limited to FFKM, PTFE, PEEK. Alternatively,the lower annular surface 115 of the tank adapter 114 may includegrooves 117 already having one or more seals disposed therein, such aso-rings, thus eliminating the need for utilizing the gasket 467.

At operation 330, the launch and recovery volume 110 and theintermediate volume 478 are purged and inerted by removing anddisplacing gases therein with an inert gas. For example, theinitially-present gases may be displaced by an inert gas such asnitrogen, argon, and the like. In one embodiment, the inert gas isinjected into the launch and recovery volume 110 through the inert gasinjection port 126, while the initially-present gas species of thelaunch and recovery volume 110 are purged through the pressure reliefport 122. Similarly, the inert gas is injected into the intermediatevolume 478 through the one or more injection ports 134, while theinitially-present gas species of the intermediate volume 478 are removedthrough the one or more release ports 132. An active, slightover-pressurization is then maintained in both the intermediate volume478 and the launch and recovery volume 110, such as a pressure less than1 psi.

At operation 340, the closure 108 is opened, thus desegregating thelaunch and recovery volume 110 and the intermediate volume 478 andforming a combined inert volume 480 between the launching system 100 andthe liquid mass 466, as depicted in FIG. 4E. Desegregation of the launchand recovery volume 110 and the intermediate volume 478 equalizes thephysical conditions, such as temperature and pressure, therebetween. Inone embodiment, the closure 108 is opened by manually sliding the gateblade 118 out from the one or more gate seats 109. In anotherembodiment, the gate blade 118 is actuated by operating a gate bladeactuator, such as by rotating a hand-wheel.

After opening the closure 108, the remote inspection device 150 istransferred into the liquid storage tank 400 at operation 350, depictedin FIG. 4F. In one embodiment, the remote inspection device 150 islowered through the combined inert volume 480 and into the liquid mass466 by rotating the handle 144 of the winch 140 and unwinding the cable142. In another embodiment, the winch 140 is operated via an electroniccontroller to wind and unwind the cable 142, thus raising and loweringthe remote inspection device 150 through the combined inert volume 480.In some embodiments, the remote inspection device 150 is moved along oneor more sets of guides 152 as it is transferred through the combinedinert volume 480. The one or more sets of device guides 152 helpstabilize the remote inspection device 150 as it is raised and loweredthrough the chamber body 102, preventing swinging thereof and collisionsof the remote inspection device 150 against the sidewalls 104. Withinthe liquid mass 466, a negative buoyancy of the remote inspection device150 enables it to sink to a storage tank floor 401 under its own weightas the cable 142 is unwound.

In one embodiment, the remote inspection device 150 automatically powerson as it is lowered into the liquid storage tank 400. For example, theremote inspection device 150 is automatically activated and/orinactivated as it reaches a desired preset depth in the liquid mass 466during launch and recovery. In such an embodiment, the remote inspectiondevice 150 includes one or more mechanical pressure switches integratedinto a power interlock system (not shown) therein. The utilization ofthe mechanical pressure switches enables the activation and/orinactivation of the remote inspection device 150 without application ofpower, thus preventing ignitions. Further, the mechanical pressureswitches ensure that the remote inspection device 150 is only powered onwhen submerged a desired depth below the surface of the liquid mass 466,thus facilitating activation of the remote inspection device 150 in anenvironment having a reduced oxygen content.

At operation 360 and depicted in FIG. 4G, the remote inspection device150 detaches from the cable 142 upon reaching the storage tank floor401. The remote inspection device 150 may then proceed with inspectionof the liquid storage tank 400 as the cable 142 is reeled back into thechamber body 102. At operation 370 and depicted in FIG. 4H, the closure108 is closed after the cable 142 has been reeled back in the chamberbody 102.

FIG. 5 illustrates a flow diagram of a representative method 500 ofrecovering a remote inspection device, such as the remote inspectiondevice 150, with the launching systems 100, 200 of FIG. 1 and FIG. 2 .FIGS. 6A-6H illustrate schematic, cross-sectional views of the launchingsystem 100 at different stages of the method 500. Thus, reference toFIGS. 6A-6H will be included in the discussion of FIG. 5 and the method500 where warranted. Although FIGS. 6A-6H depict the launching system100, it should be understood that the method 500 may be performedutilizing the launching system 200 as well.

Similar to the method 300, the method 500 for recovery of the remoteinspection device 150 has multiple operations. The operations can becarried out in any suitable order or simultaneously (except where thecontext excludes the possibility), and the method can include one ormore other operations which are carried out before any of the definedoperations, between two of the defined operations, or after all of thedefined operations (except where the context excludes the possibility).Not all embodiments include all the operations described.

In general, the method 500 includes opening the closure of the launchingsystem at operation 510 and lowering the cable into the liquid storagetank at operation 520. At operation 530, the remote inspection devicealready deployed in the liquid storage tank latches onto the cable atthe liquid storage tank floor. The remote inspection device is thenhoisted through the liquid storage tank and into the launching system atoperation 540. At operations 550 and 560, the closure is closed, theinternal volume of the launching system is re-inerted, and the liquidmass within the liquid storage tank is re-coated with the vaporsuppression foam. The launching system is then removed from the liquidstorage tank at operation 570 and the liquid storage tank is sealed atoperation 580.

In one embodiment, the method 500 begins with operation 510,corresponding to FIG. 6A. At operation 510, the closure 108 is opened,thus once again combining the launch and recovery volume 110 and theintermediate volume 478 to form the combined inert volume 480, depictedin FIG. 6B. Opening of the closure 108 equalizes the physical conditionsbetween the launch and recovery volume 110 and the intermediate volume478, such as temperature and pressure. Similar to embodiments describedabove, the closure 108 may be opened by manually sliding the gate blade118 out from the one or more gate seats 109. In another embodiment, thegate blade 118 may be actuated by operating a gate blade actuator, suchas a hand-wheel.

Optionally, prior to opening of the closure 108, the launch and recoveryvolume 110 and/or the intermediate volume 478 may be re-inerted. Forexample, the launch and recovery volume 110 and the intermediate volume478 are purged and re-inerted by removing and displacing gases thereinwith an inert gas. In one embodiment, the inert gas is injected into thelaunch and recovery volume 110 through the inert gas injection port 126,while the previously present gas species of the launch and recoveryvolume 110 are purged through the pressure relief port 122. Similarly,the inert gas is injected into the intermediate volume 478 through theone or more injection ports 134, while the previously present gasspecies of the intermediate volume 478 are removed through the one ormore release ports 132.

As depicted in FIG. 6B, after opening of the closure 108, the cable 142is unwound from the winch 140 at operation 520 and lowered into theliquid storage tank 400 until an end of the cable 142 reaches thestorage tank floor 401. In one embodiment, the cable 142 is unwound bymanually rotating the handle 144 of the winch 140. In anotherembodiment, the cable is unwound by operation of a pneumatic orhydraulic controller coupled to the winch 140.

At operation 530 and corresponding FIG. 6C, the remote inspection device150 locates the cable 142 at the storage tank floor 40 and attachesitself thereto. After attachment of the remote inspection device 150 tothe cable 142, the remote inspection device 150 is hoisted through theliquid storage tank 400 and into the chamber body 102 of the launchingsystem 100 at operation 540, as depicted in FIG. 6D. As described above,the remote inspection device 150 is hoisted through the liquid storagetank 400 and the chamber body 102 by winding of the cable 142. At adesired preset depth of the liquid mass 466, the remote inspectiondevice 150 may automatically power off by operation of one or moremechanical pressure switches integrated therein. Upon exiting the liquidstorage tank 400 and entering the chamber body 102, the remoteinspection device 150 may be coupled to the one or more sets of deviceguides 152 to position and usher the remote inspection device 150 to afinal storage position within the launching system 100. For example, theremote inspection device 150 may be guided along one or more sets oftracks longitudinally disposed within the chamber body 102 as it ishoisted through the combined inert volume 480.

Optionally at operation 540, prior to closing the closure 108 atoperation 550, one or more cleaning fluids may be supplied to the launchand recovery volume 110 by the wash port 128. For example, the wash port128 and the spray device 129 may be utilized to wash the remoteinspection device 150, the cable 142, the interior walls of the chamberbody 102, and other components or equipment within the launch andrecovery volume 110. In one embodiment, the cleaning fluids may besupplied to the launch and recovery volume 110 as the remote inspectiondevice 150 is raised therethrough, thus washing the cable 142 and theremote inspection device 150 as it is recovered from the liquid mass466. In another embodiment, the cleaning fluids are supplied to thelaunch and recovery volume 110 after the remote inspection device 150has been recovered and is secured within the launching system 100.

At operation 550 and depicted in FIG. 6E, the closure 108 is closed. Asdescribed above, the closure 108 may be closed by manually sliding thegate blade 118 into the one or more gate seats 109 of the frame 107. Inanother embodiment, the gate blade 118 may be actuated by operating agate blade actuator, such as a hand-wheel. Closing of the closure 108results in the reformation of the launch and recovery volume 110 withinwhich the remote inspection device 150 is stored. At this point, thelaunch and recovery volume 110 is re-inerted, as described above withreference to operations 330 and 510.

Upon removal of the remote inspection device 150 from the liquid mass466, the vapor suppression foam 470 may be re-injected into the opening464 at operation 560 to reform the layer of vapor suppression foam 470atop the liquid mass 466. Thus, any further volatilization and releaseof vapors form the liquid mass 466 is suppressed prior to removal of thelaunching system 100 from the opening 464. In one embodiment, the vaporsuppression foam 470 is injected into the opening 464 through a foaminjection port 134 disposed through the tank adapter 114.

At operation 570 and corresponding FIG. 6G, the launching system 100 isuncoupled and removed from the opening 464 of the liquid storage tank400. The launching system 100 is uncoupled from the opening 464 byremoving or releasing a latching mechanism 469 connecting the tankadapter 114 to the flange 465. In one embodiment, the latching mechanism469 includes one or more bolts disposed through the tank adapter 114 andthe flange 465. In another embodiment, the latching mechanism 469includes a clamp connecting the tank adapter 114 and the flange 465.Upon removal or release of the latching mechanism 469, the launchingsystem 100 is removed from the opening 464. In one embodiment, thelaunching system 100 is raised from the opening 464 by a crane or othersuitable lifting device (not shown) attached to one or more lifting lugsthereof. In an alternative embodiment, the launching system 100 israised away from the opening 464 by adjusting the transport system 260to a desired height. As depicted in FIG. 6H, once the launching system100 is removed from the opening 464, the cover plate 462 is resealedagainst the opening 464 at operation 580.

It is contemplated that one or more aspects disclosed herein may beutilized to deploy a remote inspection device within a liquid storagetank, such as a hydrocarbon storage tank, containing a hazardousenvironment therein. The application of the above-described aspectsenables thorough inspection of hydrocarbon storage tanks in a safe andefficient manner while liquid product is stored therein. In one aspect,hazardous vapors within a hydrocarbon storage tank are contained withinthe tank by utilization of a vapor suppression foam and an inertedremote inspection device launching system. The utilization of the vaporsuppression foam and the inerted launching system prevents the escape ofvolatile and hazardous vapors from releasing into the surroundingenvironment during storage tank inspection. In further aspects, theremote inspection device launched into the storage tank is configured toactivate in an environment with low oxygen content and without theapplication of external power, thus preventing ignition. Accordingly,the aspects described herein prevent the exposure of nearby personnel tohazards normally associated with hydrocarbon storage facilities.

Although the systems and processes described herein have been describedin detail, it should be understood that various changes, substitutions,and alterations can be made without departing from the spirit and scopeof the disclosure as defined by the following claims. Those skilled inthe art may be able to study the preferred embodiments and identifyother ways to practice the claimed subject matter that are not exactlyas described herein. It is the intent of the inventors that variationsand equivalents of the disclosure are within the scope of the claimedsubject matter while the descriptions, abstract, and drawings are notused to limit the scope of the claimed subject matter.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A method for inspecting a storage vessel,comprising: injecting a vapor suppression foam into a storage vessel,the vapor suppression foam forming a vapor suppression layer over aliquid mass within the storage vessel; injecting one or more inert gasesinto a volume above the vapor suppression layer; opening a closure of alaunching system coupled to the storage vessel, the launching systemcontaining an inspection device disposed therein; lowering theinspection device into the liquid mass within the storage vessel; andinspecting the storage vessel with the inspection device disposed in theliquid mass.
 2. The method of claim 1, wherein lowering the inspectiondevice into the liquid mass comprises: unwinding a cable coupling theinspection device to the launching system; uncoupling the inspectiondevice from the cable when the inspection device is in the storagevessel; winding the cable to retract a distal end thereof into thelaunching system; and closing the closure of the launching system priorto inspecting the storage vessel.
 3. The method of claim 2, furthercomprising: after inspecting the storage vessel, re-opening the closureof the launching system; unwinding the cable into the storage vessel, adistal end of the cable reaching a bottom of the storage vessel;coupling the inspection device to the distal end of the cable; windingthe cable to retract the inspection device into the launching system;re-closing the closure of the launching system; and uncoupling thelaunching system from the opening of the storage vessel.
 4. The methodof claim 3, further comprising: introducing one or more cleaning fluidsinto the launching system to wash the inspection device, the cable, andone or more sidewalls of the launching system as the inspection deviceis retracted into the launching system.
 5. The method of claim 3,further comprising: prior to re-opening the closure of the launchingsystem, re-injecting the one or more inert gases into the volume abovethe vapor suppression layer.
 6. The method of claim 3, furthercomprising: prior to re-closing the closure, re-injecting the vaporsuppression foam into the storage vessel to reform the vapor suppressionlayer.
 7. The method of claim 1, further comprising: automaticallyactivating, via a mechanical switch, the inspection device as it islowered into the liquid mass based on a pressure within the liquid mass.8. The method of claim 1, further comprising: automatically activating,via a mechanical switch, the inspection device upon reaching apredetermined depth in the liquid mass.
 9. The method of claim 1,wherein inspection of the storage vessel with the inspection device iscontrolled by a user at a remote location.
 10. The method of claim 1,wherein the inspection device autonomously inspects the storage vessel.11. A method for inspecting a storage vessel, comprising: injecting avapor suppression foam into a storage vessel, the vapor suppression foamforming a vapor suppression layer over a liquid mass within the storagevessel; opening a closure of a launching system coupled to the storagevessel, the launching system containing an inspection device disposedtherein; lowering the inspection device into the liquid mass;activating, via a mechanical switch, the inspection device upon reachinga predetermined depth in the liquid mass; and inspecting the storagevessel with the inspection device.
 12. The method of claim 11, whereinlowering the inspection device into the liquid mass comprises: unwindinga cable coupled to the launching system and the inspection device;uncoupling the inspection device from the cable when the inspectiondevice reaches a surface of the storage vessel; winding the cable toretract a distal end thereof into the launching system; and closing theclosure of the launching system upon retracting the distal end of thecable into the launching system.
 13. The method of claim 11, wherein theautomatic activation of the inspection device is based on a pressurewithin the liquid mass.
 14. The method of claim 11, wherein inspectionof the storage vessel with the inspection device is controlled by a userat a remote location.
 15. The method of claim 11, wherein the inspectiondevice autonomously inspects the storage vessel.
 16. A method forinspecting a storage vessel, comprising: injecting a vapor suppressionfoam into a storage vessel, the vapor suppression foam forming a vaporsuppression layer over a liquid mass within the storage vessel;injecting one or more inert gases into a volume above the vaporsuppression layer; opening a closure of a launching system coupled tothe storage vessel, the launching system containing an inspection devicedisposed therein; lowering the inspection device into the liquid mass;automatically activating the inspection device upon reaching apredetermined depth in the liquid mass; uncoupling the inspection devicefrom the launching system; and inspecting the storage vessel with theinspection device.
 17. The method of claim 16, wherein the automaticactivation of the inspection device is based on a pressure within theliquid mass.
 18. The method of claim 16, wherein inspection of thestorage vessel with the inspection device is controlled by a user at aremote location.
 19. The method of claim 16, wherein the inspectiondevice autonomously inspects the storage vessel.
 20. The method of claim16, further comprising: after inspecting the storage vessel, re-couplingthe inspection device to the launching system; retracting the inspectiondevice into the launching system; and closing the closure of thelaunching system.